1. Field
The present disclosure relates generally to composite components and in particular to a method and apparatus for manufacturing composite components. Still more particularly, the present disclosure relates to a method and apparatus for improving the appearance of a composite component.
2. Background
The aircraft are being designed and manufactured with greater and greater percentages of composite materials. Some aircraft may have more than fifty percent of its primary structure made from composite materials. Composite materials may be used in aircraft to decrease the weight of the aircraft. This decreased weight may improve payload capacities and fuel efficiencies. Further, composite materials may provide longer service life for various components in an aircraft.
Composite materials may be tough, light-weight materials, created by combining two or more dissimilar components. For example, a composite may include fibers and resins. The fibers and resins may be combined to form a cured composite material.
Further, by using composite materials, portions of an aircraft may be created in larger pieces or sections. For example, a fuselage in an aircraft may be created in cylindrical sections that may be put together to form the fuselage of the aircraft. Other examples may include without limitation wing sections joined to form a wing or stabilizer sections joined to form a stabilizer.
In creating composite components or structures with a curved or circular shape, the composite material may be shaped and/or laid up using a mold that may be placed against an inner mold line (IML) of a composite component. As a result, different features, textures, or appearances may be created on the inner surface of the composite component and/or composite lay up using an inner mold that contacts the inner mold line of the composite component. With a composite component in the form of a fuselage for an aircraft, these features, textures, or appearances may be used on the inside of a passenger cabin. These features, textures or appearances include, for example without limitation, windows, visible lines framing a window for aesthetics, and textures on cabin walls.
In forming a composite component from composite material, the outer surface or outer mold line (OML) of the composite material may not be subject to an outer mold when an inner mold is used. In the case of a section of a fuselage, this outer mold line may provide the outside appearance of the surface of the fuselage and/or barrel section. With this type of composite component, a smooth surface may be desired.
Depending on the size of the component, multiple caul plates may be required to be placed on the outer surface of the composite component during curing or forming of the composite component. A caul plate may be a thin gauge sheet that may be made, without limitation, of a metal or a composite material. These caul plates may be used to control the outer mold line and create a smooth surface. Large composite components may require multiple caul plates. When multiple caul plates are used, these plates may be placed next to each other. A gap may be left between adjacent caul plates to accommodate caul plate thermal expansion of the curing and/or heating processes during composite component fabrication.
At these edges of the caul plates, inconsistencies, such as a visible mark off, fiber waviness and/or fiber distortion may occur. This mark off and fiber distortion may result in a visible line or seam. This type of inconsistency may also occur if a vacuum bag contacts the composite material exposed in the gap between the caul plates and/or if the caul plates overlap during the curing process. Further, fiber waviness may occur with an unacceptable mark off or other type of inconsistency being visible on the cured composite and located in the gap between where the caul plates were during cure. These types of inconsistencies may be undesirable.
Fillers and surfacing methods may be used to reduce the visibility of these inconsistencies. In other words, the fillers may separate from the composite component prior to the scheduled repainting of the surface of the aircraft. Further, the surface of the composite component may only be lightly sanded in preparation for painting. Excessive sanding may result in an undesirable appearance of the finished aircraft.
Currently, these types of inconsistencies in the aircraft may be controlled by placing or locating caul plates such that the gaps in which inconsistencies may occur in locations on the aircraft that are not clearly visible in the finished product. These gaps may also be referred to as caul plate seams. For example, inconsistencies from caul plate seams located along a section of the fuselage where a wing is attached to the fuselage or the bottom of the fuselage may not be easily visible. Further, placing caul plates such that caul plate seams are along cut out areas for windows may also minimize inconsistencies.
Accordingly, there is a need for a method and apparatus for minimizing inconsistencies appearing on the surface of a composite component, which over comes the problems discussed above. Embodiments of the disclosure are intended to satisfy this need.